Inducible Expression of Translation Elongation Factor 1A Gene in Rice Seedlings in Response to Environmental Stresses

Differences of gene expression between salinity_stressed and control rice ( Oryza sativa L. ssp. indica ) cultivar “Zhaiyeqing 8' were compared using differential display PCR (DD_PCR) technique. Sequence analysis of one salt_inducible cDNA clone revealed that this clone represented a new member of rice translation elongation factor 1A (eEF1A) gene family and was tentatively named REF1A. Northern blot hybridization using REF1A fragment as a probe was performed to investigate the expression of rice translation elongation factor 1A gene in response to various environmental factors. It was observed that expression of the eEF1A gene in rice shoots was dramatically induced by salinity stress or exogenous application of abscisic acid (ABA). The induction of this gene by ABA stress occurred more quickly than that by salinity stress. In addition, expression of rice translation elongation factor 1A gene was also induced by drought (15% PEG6000), cold (4 ℃) or heat_shock (37 ℃) stresses. The results suggested that the induction of translation elongation factor 1A gene expression by environmental stresses might reflect the general adaptive response of rice plants to the adverse circumstances.

Cloning and Functional Analysis of the Full Length cDNA Sequence of Eukaryotic Translation Initiation Factor 5 in Schistosoma japonicum

The expressed sequence tag of eukaryotic translation initiation factor 5 （eIF5） from the Schistosoma japonicum adult worm cDNA library through subtractive hybridization between male and female worms was analyzed by the bioinformatics method. The overlapping sequences were assembled into one that includes the complete open reading frame （GenBank accession number： AY686501）. The full-length cDNA of SjeIF5 was cloned into a pET-28c^（＋） vector, which generated a prokaryotic expression plasmid, and a fusion protein of 18 kDa was induced in Escherichia coll. The recombinant expression of eIF5 protein of Schistosoma japonicum was purified. The immunoprotection test against schistosomiasis demonstrated that the recombinant protein worked to a certain extent, especially in the reduction of eggs in the liver of the host.

Stem cell pluripotency and transcription factor Oct4

Mammalian cell totipotency is a subject that has fascinated scientists for generations. A long lasting question whether some of the somatic cells retains totipotency was answered by the cloning of Dolly at the end of the 20th century. The dawn of the 21st has brought forward great expectations in harnessing the power of totipotentcy in medicine. Through stem cell biology, it is possible to generate any parts of the human body by stem cell engineering. Considerable resources will be devoted to harness the untapped potentials of stem cells in the foreseeable future which may transform medicine as we know today. At the molecular level, totipotency has been linked to a singular transcription factor and its expression appears to define whether a cell should be totipotent. Named Oct4, it can activate or repress the expression of various genes. Curiously, very little is known about Oct4 beyond its ability to regulate gene expression. The mechanism by which Oct4 specifies totipotency remains entirely unresolved. In this review, we summarize the structure and function of Oct4 and address issues related to Oct4 function in maintaining totipotency or pluripotency of embryonic stem cells.

The expression and the clinical significance of eukaryotic translation initiation factors 4E and p53 in squamous cell carcinoma

Objective： To study the expression of eukaryotic initiation factor-4E （eIF-4E） and p53 in squamous cell carcinomas （SCC） and to explore their relationship and clinical significance. Methods： The expression of elF-4E and p53 in 32 cases of SCC was detected by immunohistochemical SABC method. Results： The positive rate of elF-4E and p53 expression was 93.8% and 56.3% in SCC, and the levels of eIF-4E and p53 were significantly higher in SCC than those in the normal skin tissue （P 〈 0.05）. Conclusion： Both elF-4E and p53 were useful markers in SCC, but the specialty and sensitivity of the eiF- 4E protein was high in SCC.

Detection of eukaryotic translation initiation factor 4E and its clinical significance in hepatocellular carcinoma

AIM:To study the expression of eukaryotic translation initiation factor 4E(eIF4E),which is closely correlated with malignant tumors,and its relationship to prognosis in hepatocellular carcinoma. METHODS:Western blotting was performed to quantify the elF4E protein expression in the normal human liver cell line L02 and the hepatoma cell lines Hep3B, HepG2,and Huh7.Forty-six hepatocellular carcinoma samples with complete clinical data were obtained from Changzheng Hospital during the period of December 2008 to July 2009.The expression of eIF4E in the tumor samples and their adjacent tissues were detected by immunohistochemistry.The relationship between the test results and hepatocellular carcinoma(HCC) prognosis was statistically analysed by using a COX proportional hazard model. RESULTS:Western blotting analysis showed that there were distinct eIF4E protein bands in all three of the hepatoma cell lines.In particular,the HepG2 cell line had the highest level of eIF4E protein expression.The L02 cell group had a low eIF4E expression.Immunohistochemical assay showed that there were 32 cases in which the tumour tissue expression was higher than their adjacent tissues,accounting for 69.57%.There were also 14 cases in which the tumour tissue expression was lower or no significant difference was found, accounting for 30.43%.COX proportional hazards model analysis showed that HCC prognosis was related to the depth of invasion,the overexpression of eIF4E and p53, possibly as independent HCC prognostic predictors. CONCLUSION:In summary,eIF4E expression is associated with liver cancer,and patients with high eIF4E expression levels have a higher risk of recurrence.

Critical protein GAPDH and its regulatory mechanisms in cancer cells

Glyceraldehyde-3-phosphate dehydrogenase （GAPDH）, initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA. However, emerging evidence indicates that GAPDH is implicated in diverse functions independent of its role in energy metabolism; the expression status of GAPDH is also deregulated in various cancer cells. One of the most common effects of GAPDH is its inconsistent role in the determination of cancer cell fate. Furthermore, studies have described GAPDH as a regulator of cell death; other studies have suggested that GAPDH participates in tumor progression and serves as a new therapeutic target. However, related regulatory mechanisms of its numerous cellular functions and deregulated expression levels remain unclear. GAPDH is tightly regulated at transcriptional and pnsttranscriptional levels, which are involved in the regulation of diverse GAPDH functions. Several cancer-related factors, such as insulin, hypoxia inducible factor-1 （HIF-1）, p53, nitric oxide （NO）, and acetylated histone, not only modulate GAPDH gene expression but also affect protein functions via common pathways. Moreover, posttranslational modifications （PTMs） occurring in GAPDH in cancer cells result in new activities unrelated to the original glycnlytic function of GAPDH. In this review, recent findings related to GAPDH transcriptional regulation and PTMs are summarized. Mechanisms and pathways involved in GAPDH regulation and its different roles in cancer cells are also described.

An FPGA-based LDPC decoder with optimized scale factor of NMS decoding algorithm

Considering that the hardware implementation of the normalized minimum sum(NMS)decoding algorithm for low-density parity-check(LDPC)code is difficult due to the uncertainty of scale factor,an NMS decoding algorithm with variable scale factor is proposed for the near-earth space LDPC codes(8177,7154)in the consultative committee for space data systems(CCSDS)standard.The shift characteristics of field programmable gate array(FPGA)is used to optimize the quantization data of check nodes,and finally the function of LDPC decoder is realized.The simulation and experimental results show that the designed FPGA-based LDPC decoder adopts the scaling factor in the NMS decoding algorithm to improve the decoding performance,simplify the hardware structure,accelerate the convergence speed and improve the error correction ability.

洪荒之力 洪荒之译

2016奥运之夏,各报刊、网络媒体上,一股势不可挡的"表情"在蔓延,那就是以热词"洪荒之力"为载体的表情(包)文化。中国游泳选手傅园慧赛后这一随性表达引起全球媒体关注,其种种译文在翻译圈也引发了热议。考究种种"洪荒"之意,对各种视角译文进行受欢迎度调查,探讨如何把握翻译对象的文本语境、情景语境等微观语境,天文、历史、地理等宏观语境,以及特定的社会文化现象等"译因子",对翻译研究、实践和教学颇为有益。

Sumoylation of hypoxia inducible factor-1α and its significance in cancer

Hypoxia-inducible factor-1(HIF-1)is a key heterodimeric transcription factor for the cellular adaptive response to hypoxia,a common feature of the microenvironment in solid tumors.The transcriptional activity,protein stabilization,protein-protein interactions and cellular localization of HIF-1α,an oxygen-sensitive subunit of HIF-1,are mainly modulated by various post-translational modifications.Recently,we reported that polycomb chromobox 4(Cbx4)governs the transcriptional activity of HIF-1αby enhancing its sumoylation at K391 and K477,through which Cbx4 potentiates angiogenesis of hepatocellular carcinoma.This review summarizes the current knowledge of HIF-1α sumoylation and its roles in the pathogenesis of cancer.